Straw and residue choppers or chopper assemblies have long been in use in or with agricultural combines for chopping into finer pieces for subsequent distribution over a field the crop residue, also referred to as material other than grain (MOG), resulting from a harvesting operation. Such residue chopper assemblies have typically included a rotary chopper element disposed laterally within a housing extending generally horizontally across the flow path of the crop residue through the housing as well as a counter knife assembly extending generally parallel to and spaced from the rotary chopper element, which counter knife assembly has included a chopper grate assembly spaced below and extending generally parallel to the rotary chopper element and a knife mounting assembly positioned generally beneath the chopper grate assembly.
The rotary chopper element of the residue chopper assembly has typically had associated therewith about its periphery a number of knife blades or paddles and has included a cylindrical tube or like member having a plurality of mounting locations distributed about its periphery, at which locations the various knife blades or paddles could be mounted or affixed.
The chopper grate assembly has included a grate portion having a plurality of holes or transverse slots spaced along its length, which holes or transverse slots have typically been so sized that smaller pieces of crop residue, which may include un-separated grain, have been able to pass therethrough and enter the combine cleaning system, at least when such holes or slots have not had other elements positioned therein or extending therethrough or have not otherwise been obstructed.
The knife mounting assemblies of such prior art constructions have typically included bar-like elements extending in a fixed end-to-end arrangement with a plurality of spaced blade elements along the portion of the bar-like element generally facing the rotary chopper element, which blade elements have been aligned with slots in the grate portion of the chopper grate assembly. Such blade elements and slots in the grate portion of the chopper grate assembly have been coordinately sized and configured to permit the blade elements to be insertable into the slots to at least partially project therethrough when the knife mounting assembly is disposed in certain positions.
The knife blades or paddles of the rotary chopper element have cooperated with the blade elements of the knife mounting assembly when the knife mounting assembly is positioned such that the blade elements thereof project through the slots in the grate portion of the chopper grate assembly to chop the crop residue as it passes between the rotary chopper element and the chopper grate assembly.
Often, the counter knife assembly may have had associated therewith an adjustment mechanism that was operable to vary the spacing between the grate portion of the chopper grate assembly and the knife mounting assembly and the degree of projection of the blade elements of the knife mounting assembly through the slots of the grate portion, as may have been desirable depending upon the crop being harvested. Such an adjustment mechanism operated to move the knife mounting assembly between a fully engaged position with the blade elements of the knife mounting assembly extending through the slots towards the rotary chopper element and a fully retracted position in which the blade elements are fully withdrawn or retracted from the slots, and was typically also operable to adjustably vary the position between a fully engaged and fully retracted position.
A counter knife assembly of such general construction, whether or not the knife mounting assembly thereof has been adjustably repositionable relative to the grate portion by an adjustment mechanism, has often been referred to as a stationary knife assembly since the knife mounting assembly thereof, though perhaps adjustable to some extent to vary the distance between the rotary chopper element and the knife mounting assembly, such as by movement of the knife mounting assembly relative to the grate portion of the chopper grate assembly and the slots thereof, often in an arc-like movement about an offset axis parallel to both the rotary chopper element and the axis of the knife assembly mounting, is not rotatable about its own axis and the mounted knife blades or elements, once the knife mounting assembly has been adjustably moved to a given position, remain in essentially fixed or stationary positions during the chopping operation of the residue chopper assembly.
As noted, residue chopper assemblies employing such stationary knife assemblies have long been in use in or with agricultural combines. In the operation of a typical combine that employs a threshing rotor, the flow of crop residue or MOG remaining after threshing is typically discharged into a crop residue treatment and distribution system located below and rearwardly of the rear end of the threshing system, which crop residue treatment and distribution system typically includes a primary rotary chopper or beater apparatus or assembly that chops or beats the residue into smaller pieces and propels the resultant crop residue further rearwardly within a rear end of the combine for either discharge from the combine through a rear opening onto a field, or into another secondary chopper and/or spreader mounted on the rear end operable for spreading the residue over a swath of a field.
During a typical operation of the combine, as the crop residue is discharged from the combine rotor and moves through the crop residue treatment and distribution system it flows between the rotary chopper element of the primary chopper and the chopper grate assembly thereof. When the stationary knife assembly is in an engaged position, the crop residue is chopped into smaller pieces by the cooperative action of the knife blades or elements of the stationary knife assembly and the knife blades or paddles on the rotating rotary chopper element. The rotational movement of the rotary chopper element not only effects a cutting of the material encountered by the knife blades or paddles associated therewith but also serves to propel the resultant flow of crop residue further rearwardly.
When the stationary knife assembly is positioned to a fully retracted position, however, such as might be desirable with some crops, the crop residue passing between the rotary chopper element and the chopper grate assembly falls upon the grate portion of the chopper grate assembly, with some of the smaller crop residue pieces, including some remaining un-separated grain, falling through the slots thereof. Some of such crop residue accumulates over time on the retracted knife mounting assembly or in or at the slots of the grate portion of the chopper grate assembly and interferes with or prevents the subsequent re-engagement of the stationary knife assembly for effective chopping. When the crop residue build-up becomes significant, it does not allow the combine operator to easily engage the blade elements of the knife mounting assembly with the slots of the grate portion of the chopper grate assembly, absent removal of the build-up. Generally, removal of such build-up has had to be effected manually, resulting in additional servicing time and increased possibility of operator injury by the blade elements of the stationary knife assembly.
Foregoing the removal of the build-up and attempting to continue operation, especially over an extended period, with the stationary knife assembly in a retracted position is not generally a viable option since the rotary chopper element, by itself, due to the mechanical composition of the system, is sometimes, particularly with heavier crops or in circumstances where a heavy flow of crop residue is being introduced into the chopper assembly, not able to achieve a fast enough rotational speed to adequately desirably chop the crop residue. The chopper assembly needs to operate at an optimized throughput speed, generally as fast as possible within the limitations of the system, in order to properly chop the crop residue and to propel it rearwardly for spreading. The rotational speed realizable by the rotary chopper element is sometimes, if not often, inadequate to effect the desired chopping and throughput of the crop residue if the stationary knife assembly remains retracted or obstructed.
Consequently, users have continued to seek residue chopper assemblies that may be adjustably operated to address the various issues noted hereinabove without the necessity for frequent down time to remove accumulated crop residue build-up from stationary knife assemblies and/or grate portions of chopper grate assemblies and without the need to deal with the accompanying safety hazards. The present invention, as discussed and described hereinafter, addresses such a construction and its use.